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In the C program below, I make a mistake and call the function with (ld, ld) instead of (d, ld). #include <stdio.h> #include <limits.h> void print_int_long(int n, long l){ pri...
#3: Post edited
by
Lundin
·
2021-04-22T14:25:33Z (almost 3 years ago)
#2: Post edited
by
Alexei
·
2021-04-22T05:32:44Z (almost 3 years ago)
added relevant tag
#1: Initial revision
by
Quasímodo
·
2021-04-21T19:34:38Z (almost 3 years ago)
Warn of implicit cast in a function's arguments with GCC?
In the C program below, I make a mistake and call the function with `(ld, ld)` instead of `(d, ld)`.
```c
#include <stdio.h>
#include <limits.h>
void print_int_long(int n, long l){
printf("%+d %+ld\n", n, l);
}
int main(){
int d = 0;
long ld = INT_MAX + 1L;
print_int_long(ld, ld);
return(d);
}
```
If lucky, such mistakes may be innocuous, but here it is not: Instead of `+0 +2147483648` I get `-2147483648 +2147483648` because of an integer overflow.
Of course, this is but a dumb example, but I would like to be warned if I make such mistake in a real program. **Is there any GCC flag that will detect and warn about this kind of implicit cast?** I am used to `-Wall -Wpedantic -Wextra` but those did not raise a warning. I have also looked in [GCC warning options][1] but I failed to find something.
Always open to other approaches too.
[1]: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html